The aim of this research program is to see whether or not the small movements of the eye contribute to sensitivity of the visual system. To this end we have been using the stabilized image method to render the retinal image stationary. We compare measures of sensitivity obtained with a stabilized image to the measures obtained when the image moves normally on the retina. So far, in this last grant period we were able to demonstrate that elevation of increment thresholds near a luminance border is in a large part due to retinal image motion. We have also been engaged in recording from retinal ganglion cells with the aim of exploring variation in receptive field size as a function of eccentricity. This knowledge we hope will aid us in choosing between two viewpoints on retinal mechanisms subserving contrast sensitivity.